This invention relates to log-type building constructions, particularly improvements in means for joining the logs together at corners and intersections in such building constructions.
The prior art has provided various means for interlocking wall members of a building construction. One such construction is shown in Canadian Pat. No. 422,498 dated Sept. 5, 1944 to Fraser. This patent discloses an interlocking construction including a plurality of wall members adapted to be placed one on top of the other. Aligned mortises are formed in the members with the mouth or entrance of each mortise being narrower than its base. Locking units are provided which are capable of overlapping at least part of each of two of more wall members. Each locking unit is provided with tenons which are shaped to fit into the mortises with such unit locking the members together when their tenons are fitted into the specially shaped mortises. When it is desired to form a corner with this construction, the ends of two walls, each formed of a plurality of wall members, are brought together at an angle to each other. As shown in the patent, the adjacent ends of the walls are cut at an oblique angle such that the wall members contact each other at the extreme outer edge of the corner construction. The preferred embodiment illustrated by Fraser employs tongues and grooves in the opposite edges of the wall members as well as in the locking units.
The Fraser construction is relatively costly to manufacture in that special tools and manufacturing processes are required to form the mortises in the wall members and the specially shaped tenons on the locking units. Shrinkage of the wood may cause the tenons to split off from the remainder of the locking units or, alternatively, for the mouth or entrance portion of the mortise to split off along the grain of the wood with the result being that the corner of the building is left substantially unsupported and liable to failure.